3. A 50.0 gram piece of iron (specific heat = 0.450 J/g-C°) is heated to 100. C° in boiling water and then dropped into 80.0 grams of water at
22.0 C° Calculate the equilibrium temperature.

The answer for #3 is c but i don't know why

Phosphorous acid, h3po3(aq) , is a diprotic oxyacid that is an important compound in industry and agriculture. p k a1 p k a2 1.30 6.70 calculate the ph for each of the points in the titration of 50.0 ml of 1.5 m h3po3(aq) 1.5 m h 3 po 3 ( aq ) with 1.5 m koh(aq). 1.5 m koh ( aq ) .

What is the mass of phosphorous in a 51-kg person